The Pentlands are a series of hills SW of Edinburgh, starting right on the outskirts. There are lots of ways onto the hills, and many require cars to be convenient, however bus access is easy from Hillend, Bonaly, Flotterstone and Carlops, so longs you time it right.
If you're visiting Edinburgh, you should really try to get out of town for a day. Why not build that into your programme? The details below recommend a short walk for those who like country but not hills, of a full day out for those who need to regenerate after a few days around town.
Flotterstone is recommended for gentle walks of any length, a road from there penetrates into the middle of the hills, passing two reservoirs. You might see dippers, cuckoos Peregrines depending on where and when. Take a picnic.
http://www.streetmap.co.uk/map.srf?X=321852&Y=662955&A=Y&Z=120 for map details, but you can see the rout on the day at the Ranger Centre.
I'll look at Hillend as a starting point for ascents to some tops.
Firstly there's a nice pub at the bottom of the hill, with good food, so mark it down for the return leg. There's a short road up to the ski centre if you want to gain a little height before walking.
From the ski centre you can head straight South (and straight up) and there are paths which zigzag up the hills past the ski slopes, coming out on Caerketton Hill at a height of about 480 metres (over 1500 feet)
Again from the Ski Centre you can walk up the woodlands on the right hand side then strike due West, traversing the hillside. You can then ascend either the left or the right of Allermuir Hill 490 metres (about 1600 feet).
I recommend you go up one way and down the other. The two peaks are no distance apart.
About 1 hour 30 minutes if you crack on at a good speed, two hours or more if you'e more relaxed (?) about ascending.
The classic Pentlands day out.
I usually take a bus down to Carlops and walk a number of tops heading back to Edinburgh. This can be shortened somewhat by getting off the bus at Ninemileburn.
At the N end of Carlops there's a little footpath heading onto the hills. You can follow this awhile, then ascend rightwards up the slopes until you can see more clearly you have now hit a ridge. From then on (in good weather) it's plain sailing, and the route goes Patie's Hill, Spittal Hill, Greenlaw, East Kip, West Kip, Scald Law, Carnethy, Turnhouse. From there you can descend to Flotterstone Inn (pub, car park, ranger centre, bus)
Here's the first part as a map: http://www.streetmap.co.uk/map.srf?X=316672&Y=657215&A=Y&Z=120
Alternatively you could descend NE to Glencorse reservoir, cross the road and then ascend West of Castlelaw Hill, then climbing Allermuir and Caerketton, before descending to the ski centre and then to the main road (good pub, buses).
The full route is a proper day out with quite a few miles, mostly on decent paths but quite a lot of up and down. Call it 20 Km, and over 1000 metres ascent, making a 5-6 hour journey at least, probably longer. Even the shorter route to Flotterstone is not for the unfit at 13-14 Km and over 700 metres of ascent making a 4-5 hour trip, even at a decent pace.
I like hills and mountains and I'm out in the Pentlands regularly. The long route is my favourite Pentlands leg-stretcher. If you too like hills you won't regret a permutation of the above: nice hills, you'll bump into a few nice people along the way, and the views are superb especially from Allermuir northwards.
None of the above is technically difficult but you need to be hill-fit to get the best out of it. And it's boots not shoes ...
If you're visiting Edinburgh and thinking about a walk, you an always 'ask' me a question and I'll try to help.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.